Physical Sciences and Mathematics Commons^™

New Upper Limit On The Decay Η→E+E-, T. E. Browder, Kenneth A. Bloom, Cleo Collaboration

Kenneth Bloom Publications

We have searched for the rare decay of the η meson η→e⁺e^- using the CLEO II detector. The η’s were produced in e⁺e^- collisions with 10 GeV center-of-mass energy at the Cornell Electron Storage Ring (CESR). We find with 90% confidence the upper limit on the branching fraction B (η→e⁺e^-)<7.7×10^-5. The application of conventional elementary particle theory to this decay predicts a branching fraction of about 10^-9.

Stratospheric Loading Of Sulfur From Explosive Volcanic Eruptions, Gregg J. Bluth, William I. Rose, Ian E. Sprod, Arlin J. Krueger

Department of Geological and Mining Engineering and Sciences Publications

This paper is an attempt to measure our understanding of volcano/atmosphere interactions by comparing a box model of potential volcanogenic aerosol production and removal in the stratosphere with the stratospheric aerosol optical depth over the period of 1979 to 1994. Model results and observed data are in good agreement both in magnitude and removal rates for the two largest eruptions, El Chicho´n and Pinatubo. However, the peak of stratospheric optical depth occurs about nine months after the eruptions, four times longer than the model prediction, which is driven by actual SO2 measurements. For smaller eruptions, the observed stratospheric perturbation is …

State Of The Fisheries Report 1996/1997, Jim W. Penn

Status Reports of the Fisheries and Aquatic Resources

The State of the Fisheries document is designed as an essential supplement to the Annual Report to Parliament. By summarising data such as landings, ettort, catch rates, stock assessment and breeding stock levels, this document provides a valuable reference point for all Western Australian fisheries of major importance to the commercial, recreational and aquaculture sectors. Information relevant to the Department of Fisheries' Fish and Fish Habitat Protection Program is also provided. The report indicates that overall the major fish stocks which support fisheries in Western Australia continue to be in a reasonably healthy condition. Those species which are being harvested …

Vertical Profiles Of Bromoform In Snow, Sea Ice, And Seawater In The Canadian Arctic, William T. Sturges, Glenn F. Cota, Paul T. Buckley

CCPO Publications

Bromoform (CHBr₃) was measured in vertical profiles from the snow surface through the snowpack, sea ice, and water column to the seafloor at Resolute Bay, Canada, in the sprig of 1992. Elevated concentrations of bromoform were observed in both the ice (32-266 ng L^-1 by liquid water volume) and seawater (~ 20 ng L^-1 ) at the ice-water interface, associated with bromoform emission from ice microalgae. A surprising finding was a second horizon of high bromoform concentrations (336-367 ng L^-1) in sea ice at the snow-ice interface. Chlorophyll and salinity were also elevated in …

Nonlinear Response Theory: Transport Coefficients For Driving Fields Of Arbitrary Magnitude, Paul Ernest Parris, Marek Kus, David H. Dunlap, Vasudev M. Kenkre

Physics Faculty Research & Creative Works

A theory of nonlinear response is developed for driving fields of arbitrary magnitude. Exact and usable expressions are provided for electrical and thermal mobility, and related transport coefficients, in terms of correlation functions of the system. A generalization into the nonlinear domain is provided of the Wiedemann-Franz law connecting electrical and thermal response and of the Einstein relation relating the diffusion constant and the mobility.

An Investigation Into The Use Of Software Product Metrics For Cobol Systems, Richard E. Boone

Theses and Dissertations

This thesis investigated several hypotheses that specific product measures could be used to predict later software lifecycle process or product measures. It collected software product and process measures from four consecutive major releases of a large Cobol legacy system (400K LOC). The types of product measures used were size and specific complexity measures. A statistical software package was used to calculate sample correlation coefficients between the measures. A 95% confidence interval was computed for each sample correlation coefficient that showed a strong or moderate linear correlation. The maintenance process measures provided were manhours used for each program changed or added, …

A Validation Of The Parameterized Real-Time Ionospheric Specification Model (Prism) Version 1.7b, Shawn D. Filby

Theses and Dissertations

The most current version of the Parameterized Real-time Ionospheric Specification Model (PRISM), version 1.7b, was validated using Digital Ionospheric Sounding System (DISS) measurements of F2 layer critical frequency (foF2) and F2 peak electron density height (hmF2) as the "ground truth." PRISM was executed, first, with no real-time input parameter and, second, with Global Positioning System (GPS) Total Electron Content (TEC) measurements as the sole real-time parameter. Hourly values of hmF2 and foF2 over 123 days in 1994-1996 (solar minimum conditions) and covering three seasons (equinox, summer solstice, and winter solstice) were compared for Wallops Island, Virginia, and Point Arguello, California, …

Coordinate Regulation Of G- And C Strand Length During New Telomere Synthesis, Xinqing Fan, Carolyn Mary Price

Department of Chemistry: Faculty Publications

We have used the ciliate Euplotes to study the role of DNA polymerase in telomeric C strand synthesis. Euplotes provides a unique opportunity to study C strand synthesis without the complication of simultaneous DNA replication because millions of new telomeres are made at a stage in the life cycle when no general DNA replication takes place. Previously we showed that the C-strands of newly synthesized telomeres have a precisely controlled length while the G-strands are more heterogeneous. This finding suggested that, although synthesis of the G-strand (by telomerase) is the first step in telomere addition, a major regulatory step occurs …

Search For The Decay Τ-→4Π-3Π+(Π0)ΝΤ, K. W. Edwards, Kenneth A. Bloom, Cleo Collaboration

Kenneth Bloom Publications

We have searched for the decay of the τ lepton into seven charged particles and zero or one π⁰. The data used in the search were collected with the CLEO II detector at the Cornell Electron Storage Ring (CESR) and correspond to an integrated luminosity of 4.61 fb^-. No evidence for a signal is found. Assuming all the charged particles are pions, we set an upper limit on the branching fraction B(τ^-→4π^-3π⁺(π⁰) ν_τ) < 2.4X10^-6 at the 90% confidence level. This limit represents a significant improvement …

Tertiary Storage In Multimedia Systems: Staging Or Direct Access?, Hwee Hwa Pang

Research Collection School Of Computing and Information Systems

Multimedia applications that are required to manipulate large collections of objects are becoming increasingly common. Moreover, the size of multimedia objects, which are already huge, are getting even bigger as the resolution of output devices improve. As a result, many multimedia storage systems are not likely to be able to keep all of their objects disk-resident. Instead, a majority of the less popular objects have to be off-loaded to tertiary storage to keep costs down. The speed at which objects can be accessed from tertiary storage is thus an important consideration. In this paper, we propose an adaptive data retrieval …

Searches For Scalar Top And Scalar Bottom Quarks At Lep2, Barate, R.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

Searches for scalar top and bottom quarks have been performed with data collected by the ALEPH detector at LEP. The data sample consists of 21.7 pb−1 taken at √ s = 161, 170, and 172 GeV and 5.7 pb−1 taken at √ s = 130 and 136 GeV. No evidence for scalar top quarks or scalar bottom quarks was found in the channels ˜t → cχ, ˜t → bℓν˜, and b˜ → bχ. For the channel ˜t → cχ a limit of 67 GeV/c 2 has been set on the scalar top quark mass, independent of the mixing angle between …

An Integrated Environment For Problem Solving And Program Development, Fadi Pierre Deek

Dissertations

A framework for an integrated problem solving and program development environment that addresses the needs of students learning programming is proposed. Several objectives have been accomplished: defining the tasks required for program development and a literature review to determine the actual difficulties involved in learning those tasks. A comprehensive Study of environments and tools developed to support the learning of problem solving and programming was then performed, covering programming environments, debugging aids, intelligent tutoring systems, and intelligent programming environments. This was followed by a careful analysis and critique of these systems, which uncovered the limitations that have prevented them from …

Modeling Study On The Neopentyl+ O2 Reaction System And Experimental And Modeling Study On Mtbe Pyrolysis And Oxidation, Ru Wei

Dissertations

A modeling study on neopentyl radical + O₂ reaction system is conducted in this study. Thermodynamic parameters on all species and important transition states are calculated. A thermochemical kinetic analysis is performed.

Thermodynamic parameters are estimated using group additivity with HBI groups. Transition state energies are evaluated from experimental and theoretical data in the literature, combined with elementary reaction modeling to account for temperature effects. Transition state structures, vibration frequencies and entropies are determined from semi-empirical calculations, MOPAC PM3. Kinetics are analyzed with quantum RRK theory for k(E) coupled with modified strong collision analysis of Gilbert et al for …

Diffusive And Wavelike Phenomena In Thermal Processing Of Materials, John A. Pelesko

Dissertations

Contemporary materials science abounds with novel processing methods. Devices such as lasers, microwave sources, and electron beam guns, provide unprecedented control over the deposition of energy within a material. The modern materials scientist has the ability to deposit energy volumetrically, to precisely control the location of energy deposition within a material, and to deposit energy in extremely short intervals of time. While making possible numerous thermal processing methods, these devices also push the limits of our understanding of the response of materials to energy deposition. In order to optimize and control these processing methods, it becomes necessary to further our …

Hybrid Quantum And Molecular Mechanics Embedded Cluster Models For Chemistry On Silicon And Silicon Carbide Surfaces, James R. Shoemaker

Theses and Dissertations

Fabrication of silicon carbide SiC semiconductor devices are of interest for aerospace applications because of their high-temperature tolerance. Growth of an insulating SiO₂ layer on SiC is a poorly understood process, and sometimes produces interface defects that degrade device performance. Accurate theoretical models of surface chemistry, using quantum mechanics QM, do not exist because of the huge computational cost of solving Schroedingers equation for a molecular cluster large enough to represent a surface. Molecular mechanics MM, which describes a molecule as a collection of atoms interacting through classical potentials, is a fast computational method, good at predicting molecular structure, …

Removal And Recovery Of Vocs And Oils From Surfactant-Flushed Recovered Water By Membrane Permeation, Ashish Nagnath Saraf

Theses

Surfactant-enhanced subsurface remediation appears to be capable of removing efficiently contaminants from the source area as well as the concentrated plume. Initial research was conducted on separate removal of trichloroethylene (TCE) and an oil. It was found that oil permeation and modified pervaporation are effective techniques of removing oil and TCE respectively from the simulated feed. It was found that the oil permeation technique can effectively remove 98-99% of oil from an oil-in-water emulsion. The subsurface-entrapped organic pollutants often have high boiling components along with the VOCs. A combined permeation technique is applied here to simultaneously remove TCE and n-dodecane …

Interactive And Batch Creation Of Oodb Medical Vocabularies, Muhammad Arif

Theses

Controlled vocabularies are becoming popular for knowledge representation and querying. They are particularly helpful in the medical field since they can unify disparate terminologies and provide information in a compact, comprehensible manner. In this thesis, we present a mechanism to create OODB controlled medical vocabularies from flat-file format. We also describe a tool by which a user can interactively create, edit and browse the vocabulary. For better understanding of the structure of the vocabulary we designed our interface as a graphical editor and browser. The user of this interface will typically be a medical expert who either wants to add …

Structured Document Comparison And Scientific Data Mining On The World Wide Web, Philip B. Johnson

Theses

The usefulness and accessibility of programs and systems have become important issues for users and researchers alike. A program's usefulness can lw measured by the frequency with which it is used. From the author's or maintainer's point of view, the frequency of usage can be determined by how often a request for the software is received. In the past, a user became aware of a particular tool through various means, and contacted the author or maintainer to obtain a copy of it. This presented difficulties, ranging from language barriers to machine incompatibilities to control of the use of the program. …

Testing Statistical Significance In Sequence Classification Algorithms, Tom Tien-Hua Shih

Theses

Multiple sequence alignment has proven to be a successful method of representing and organizing of protein sequence data. It is crucial to medical researches on the structure and function of proteins.

There have been numerous tools published on how to abstract meaningful relationship from an unknown sequence and a set of known sequences. One study used a method for discovering active motifs in a set of related protein sequences. These are meaningful knowledge abstracted from the known protein database since most protein families are characterized by multiple local motifs. Another study abstracts knowledge regarding the input sequence using a preconstructed …

Analysis Of The Protocol For The Handover In A Micro-Cell Packet Switched Mobile Network, Anna M. Thomas

Theses

The overlay of microcells over macrocells offers new opportunities and is cost effective, which makes the handover in such a micro-cellular environment an important issue. The objective of this study is to analyze and prove the truthfulness of a new protocol proposed, which guarantees no packet loss during the handoff. The study here emphasizes on the data integrity issue, since it is the key factor affecting the throughput performance of the transport layer. It is shown that usage of the Internet Protocol leads to packet loss in the presence of handover. Simulation results reveal that the proposed new protocol preserves …

Algorithms And Tools For Splicing Junction Donor Recognition In Genomic Dna Sequences, Maisheng Yin

Theses

The consensus sequences at splicing junctions in genomic DNA are required for pre-mRNA breaking and rejoining which must be carried out precisely. Programs currently available for identification or prediction of transcribed sequences from within genomic DNA are far from being powerful enough to elucidate genomic structure completely[4]. In this research, we develop a degenerate pattern match algorithm for 5' splicing site (Donor Site) recognition.. Using the Motif models we developed, we can mine out the degenerate pattern information from the consensus splicing junction sequences. Our experimental results show that, this algorithm can correctly recognize 93% of the total donor sites …

Port Everglades Macroinvertebrate Monitoring: Monitoring Of Benthic Macroinvertebrate Assemblages At The Southport Turning Basin And Adjacent Areas Of John U. Lloyd State Recreation Area: Final Report, Charles G. Messing, Richard E. Dodge

Marine & Environmental Sciences Faculty Reports

Monitoring of benthic macroinvertebrate assemblages in the vicinity of Port Everglades Southport began in September 1988 in anticipation of dredging of the Southport Turning Notch and concomitant mitigation of mangrove habitats at adjacent areas of John U. Lloyd State Recreation Area. Twice-yearly surveys were carried out from September 1988 to January 1991 by Sheldon Dobkin (Florida Atlantic University), and subsequently, from August 1991 to January 1997, under the supervision of Charles G. Messing and Richard E. Dodge (Nova Southeastern University Oceanographic Center). From 1990 onward, surveyed sites consisted of 11 Ponar grab stations, 11 mangrove crab census stations, and three …

Terrestrial Natural Communities Of Nebraska - Version I, Gerry Steinauer, Steven B. Rolfsmeier

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

The Nebraska Natural Heritage Program has been collecting information and data including published literature, field observations and vegetation plot data over the last 10 years of development of Nebraska’s natural community classification. The classification contains 27 wetland and 36 upland communities including forest, woodland, shrubland, herbaceous, and sparsely vegetated (e.g. rock outcrop) types. The community types were distinguished primarily on plant species composition and to a lesser extent on soils, hydrology and geographic location. The classification contains descriptions of each community type that include dominant species, soils, range, and other ecological information. The classification is designed to be flexible enough …

Materialized View Algorithms, Yubo Fan

Dissertations and Theses

A data warehouse is a stand-alone repository of integrated information available for decision support OLAP querying and analysis. Aggregate views can be materialized (stored in disk) to improve query performance in a data warehouse.

Several static and dynamic algorithms for selecting materialized aggregate views (MAV) in a data warehouse are proposed in this thesis. The algorithms are then compared by running a simulation system, which can be configured to compare several algorithms on different type of data warehouses. Simulation results for static algorithms are presented to show that several proposed algorithms perform close to an existing good algorithm (HRU Greedy) …

Role Of Multiple Scattering In Cross-Correlated Light Scattering With A Single Laser Beam, James A. Lock

Physics Faculty Publications

Previous systems for measuring cross-correlated light scattering by small particles suspended in a liquid with multiple-scattering suppression have illuminated the particles with two laser beams. It is shown that multiple-scattering suppression should also occur in cross correlation for a system that employs a single laser beam and two closely spaced detectors with wide fields of view. The single-scattering, double-scattering, and single-double-scattering cross-term contributions to the intensity cross-correlation function are calculated. It is found that the two cross terms, when added together, are unimportant for both autocorrelation and cross correlation. The amplitude of the double-scattering term can be greatly diminished by …

Hybrid Reflection-Transmission Surface Light-Scattering Instrument With Reduced Sensitivity To Surface Sloshing, William V. Meyer, James A. Lock, H. Michael Cheung, Thomas W. Taylor, Padetha Tin, J. Adin Mann

Physics Faculty Publications

A hybrid reflection-transmission surface light-scattering instrumental design is presented, examined theoretically, and tested experimentally. The purpose of the design is to reduce the sensitivity of the instrument to vibration in general and surface sloshing in particular while sacrificing Little performance. Traditional optical arrangements and two new optical configurations with varying trade-offs between slosh resistance and instrumental simplicity and accuracy are examined by use of Fourier optics methods. The most promising design was constructed and tested with acetone, ethanol, and water as subject fluids. The test involved backcalculation of the wave number of the capillary wave examined with the known physical …

Multiple-Scattering Suppression By Cross Correlation, William V. Meyer, David S. Cannell, Anthony E. Smart, Thomas W. Taylor, Padetha Tin

Physics Faculty Publications

We describe a new method for characterizing particles in turbid media by cross correlating the scattered intensity fluctuations at two nearby points in the far field. The cross-correlation function selectively emphasizes single scattering over multiple scattering. The usual dynamic light-scattering capability of inferring particle size from decay rate is thus extended to samples that are so turbid as to be visually opaque. The method relies on single-scattering speckle being physically larger than multiple-scattering speckle. With a suitable optical geometry to select nearby points in the far field or equivalently slightly different scattering wave vectors (of the same magnitude), the multiple-scattering …

Fiber-Optics Surface-Light-Scattering Spectrometer, Padetha Tin, J. Adin Mann, William V. Meyer, Thomas W. Taylor

Physics Faculty Publications

We have developed a fiber-optics surface-light-scattering spectrometer completely designed with optical fiber components. To the best of our knowledge, this is the first demonstration of a noninvasive measurement of the surface tension and the viscosity of simple liquid-vapor interfaces with a fiber-optics-based sensor system. With this approach we obtain a compact size, a significant increase in the signal-to-noise ratio, and the ability to select from a continuum of wave vectors. (C) 1997 Optical Society of America.

Hybrid Reflection-Transmission Surface Light-Scattering Instrument With Reduced Sensitivity To Surface Sloshing, William V. Meyer, James A. Lock, Michael Cheung, Thomas W. Taylor, Padetha Tin, J. Adin Mann Jr.

Chemical, Biomolecular, and Corrosion Engineering Faculty Research

A hybrid reflection-transmission surface light-scattering instrumental design is presented, examined theoretically, and tested experimentally. The purpose of the design is to reduce the sensitivity of the instrument to vibration in general and surface sloshing in particular while sacrificing Little performance. Traditional optical arrangements and two new optical configurations with varying trade-offs between slosh resistance and instrumental simplicity and accuracy are examined by use of Fourier optics methods. The most promising design was constructed and tested with acetone, ethanol, and water as subject fluids. The test involved backcalculation of the wave number of the capillary wave examined with the known physical …

Potential Demand For Programs On Nuisance Wildlife Among Wildlife-Related Program Offerings To Urban/Suburban Organizations, S. M. Leslie, P. F. Scanlon, O. T. Clarke

Wildlife Damage Management Conference

Program planners of 114 organizations in the Roanoke Valley area of Virginia responded to the likelihood of their scheduling programs on wildlife-related topics. Among the topics offered was “Controlling Wildlife Pests and/or Their Damage.” Responses were organized by type of organization (civic club, neighborhood organization, educational/PTA organization, environmental/hobby organization, garden/plant club) and whether they were “highly likely” (HL), “somewhat likely” (SL), “not likely” (NL), or “not sure” (NS) they would schedule such a program. Results on likelihood of scheduling were as follows: 31 civic clubs (1 HL, 4 SL, 33NL, 4 NS); 26 neighborhood organizations (5 HL, 7 SL, 5 …